Quantitative Strength Measurements Research Articles

Outcomes Following Plate Fixation of Fractures of Both Bones of the Forearm in Adults

Internal fixation of diaphyseal forearm fractures has been associated with high union rates and satisfactory forearm motion. The purpose of this study was to investigate patient-based functional outcomes and to objectively measure strength following plate fixation of fractures of both bones of the forearm. Range of motion, quantitative strength measurements, and validated outcome measures-i.e., DASH (Disabilities of the Arm, Shoulder and Hand) and SF-36 (Short Form-36) scores-were assessed in a cohort of thirty patients (nineteen men and eleven women with a mean age of 43.9 years) treated with plate fixation for fractures of both bones of the forearm. The mean duration of follow-up was 5.4 years, and standardized radiographs of the forearm were evaluated. Univariate and multivariate analyses were performed to identify determinants of the DASH and SF-36 Physical and Mental Component Summary (PCS and MCS) scores. Compared with the uninjured arms, the injured arms had reduced strength of forearm pronation (70% of that of the normal arm, p < 0.0001), forearm supination (68%, p < 0.0001), wrist flexion (84%, p = 0.0011), wrist extension (63%, p < 0.0001), and grip (75%, p < 0.0001). In addition, the injured arms had a significantly reduced active range of forearm supination (90% of that of the uninjured arm, p = 0.0001), forearm pronation (91%, p = 0.0028), and wrist flexion (82%, p < 0.0001). The mean DASH score (18.6 points; range, 0 to 61 points) was significantly higher than the normative value in the United States (p = 0.02). Limitations in strength correlated with worse DASH and SF-36 PCS scores. Pain and a work-related injury were independent determinants of the DASH score. Stabilization with internal plate fixation following fracture of both bones of the forearm restores nearly normal anatomy and motion. However, a moderate reduction in the strength of the forearm, the wrist, and grip should be expected following this injury. Perceived disability as measured with the DASH and SF-36 questionnaires is determined by pain more than by objective physical impairment.

Immediate, full weightbearing cast treatment of acute Achilles tendon ruptures: a long-term follow-up study.

Thirty-two patients with 33 ruptures were available for comprehensive evaluation, which included a questionnaire, physical examination, and manual as well as objective (Kin-Com) strength testing. Data excluding Kin-Com strength testing were available in an additional seven patients with seven ruptures; hence, the data are based on these 39 patients with 40 ruptures. Five patients with eight ruptures were excluded from strength testing but were included in our rerupture data, which totaled 44 patients with 48 ruptures. All patients were treated using a standard protocol by a single surgeon. All patients were treated within 11 days of injury, and the average follow-up was 55 months (range, 24-133). Ninety-five percent (38/39) of patients were completely satisfied with their treatment. The American Orthopaedic Foot and Ankle Society (AOFAS) ankle hindfoot scores were >80 in 97.4% of patients, and the rerupture rate was 6.25% (3/48). Calf circumference and ankle range of motion were not statistically different between the two legs. The injured leg tended to be slightly weaker than the uninjured leg, but the difference was not significant for most of the quantitative strength measurements. This study provides data for the Achilles rupture patient who asks, "Is there a treatment option other than surgery?" In addition, the standardized protocol can be utilized to obtain successful outcomes in those who choose nonoperative treatment or are poor surgical candidates.

Movement compatibility for rotary control and circular display—Computer Simulated Test and real Hardware Test

This experiment studied strength and reversibility of direction-of-motion stereotypes and response times for different configurations of circular displays and rotary knobs. The effect of pointer position, instruction of turn direction, and control plane on movement compatibility was analyzed with precise quantitative measures of strength and reversibility index of stereotype. A comparison of results was made between a Computer Simulated Test and a Hardware Test with real rotary controls. There was consensus in the results of the two tests that strong and significantly reversible clockwise-for-clockwise (CC) and anticlockwise-for-anticlockwise (AA) stereotypes were obtained at the 12 o’clock position. Subjects’ response times were found to be generally longer when there were no clear movement stereotypes. Nevertheless, differences of results were observed that while the CC and AA preferences were found to be dominant and reversible at all the planes and pointer positions in the Hardware Test, there was variation in the strength and reversibility of the two stereotypes amongst different testing configurations in the Simulated Test. This phenomenon was explained by the operating of the clockwise-for-right and anticlockwise-for-left principles, as shown in the analysis of contributions of component principles to the overall stereotype. The differences of results from the two tests were discussed with regard to simulation fidelity and it was suggested that a real Hardware Test should be used whenever possible for determination of design parameters of control panels in consideration of movement compatibility. Based on the Hardware Test, a pointer is recommended to be positioned at 12 o’clock position for check reading or resetting purpose, and the frontal plane is the best plane for positioning a rotary control with circular display. The results of this study provided significant implications for the industrial design of control panels used in man–machine interfaces for improved human performance.

IgM antibody-related polyneuropathies: B-cell depletion chemotherapy using Rituximab.

Current treatments for anti-GM1 ganglioside or antimyelin-associated glycoprotein (anti-MAG) antibody-associated polyneuropathies are toxic or very costly. In this preliminary study the authors treated five patients with neuropathy and immunoglobulin M antibodies to GM1 ganglioside or MAG by depleting B cells using Rituximab--a monoclonal antibody directed against the B-cell surface membrane marker CD20. Within 3 to 6 months after treatment, all five patients had improved function, significantly increased quantitative strength measurements, and reduced titers of serum autoantibodies.

Inter-rater reliability for function and strength measurements in the acute care hospital after elective hip and knee arthroplasty.

To determine the inter-rater reliability of function and strength measurements in patients undergoing elective hip and knee arthroplasty in an acute care setting. Forty-four patients underwent either total hip or knee arthroplasty. Patients were rated by 4 occupational therapists and 7 physical therapists on their performance of 5 functional tasks: lower extremity dressing, toilet transfer, supine-to-sit transfer, sit-to-stand transfer, and ambulation to 100 feet. Strength measurements of the quadriceps femoris muscle were measured quantitatively with a Microfet hand-held dynamometer. Data were analyzed to determine the interrater reliability using the Kappa statistic (K) for the functional tasks and the intra-class correlation coefficient (ICC) for the strength measurements. A high level of inter-rater reliability was achieved for lower extremity dressing, toilet transfer, supine-to-sit transfer, sit-to-stand transfer, and ambulation to 100 feet, as evidenced by K values between 0.75 and 0.99. Reliability was also excellent for quantitative strength measurements using the dynamometer, with an ICC of 0.94. This study demonstrated excellent interrater reliability with measurements of function and strength post-operatively after elective hip and knee arthroplasty. The practical implication is that by using a standardized measurement tool in the acute care setting, the treatment team can more reliably assess patients' progress, which may aid clinical decision making.

Profiles of neuromuscular diseases. Limb-girdle syndromes.

Sixty-six individuals with Limb-Girdle Syndrome (LGS) were evaluated over a 10-yr period and classified into three types: 19 severe autosomal recessive muscular dystrophy of childhood (ARMDC), alternatively referred to by some as SCARMD, 18 autosomal dominant late onset (ADLO), and 29 pelvifemoral (PF) individuals. ARMDC subjects showed the greatest weakness, 2.5 +/- 1.0, mean Manual Muscle Test (MMT) grade for all muscles combined, and the only significant progression of loss of strength, -0.59 MMT unit decline per decade. Strength loss in ADLO and PF types was about the same, 3.7 +/- 0.7 and 4.0 +/- 0.7 grades, respectively. Quantitative strength measurements in ADLO and PF types were more sensitive than MMTs, showing losses of 30-40% strength in muscle groups with MMT grades of 4 or higher. All three types showed greater proximal and lower extremity weakness but usually no difference between flexor and extensor strength. There was a high percentage (44%) of mild very slowly progressive scoliosis in ARMDC, but spine deformity was unusual in ADLO and PF (11%) LGS. Contractures were few, slowly progressive, and usually mild in severity in all types, although more frequent in ARMDC. There also was a low frequency of severe restrictive lung disease in all types (10%) but a high percentage of electrocardiogram abnormalities (62-73%). The most common electrocardiogram abnormalities were increased R/S ratio in V1 and infranodal conduction defects. Intellectual and cognitive functions were within normal limits. Mobility and extremity function reflected the strength differences between the ARMDC and other types of LGS. Eight-five percent of ARMDC individuals relied on a wheelchair for all or part of their mobility, and all were unable to complete timed motor performance tests within the 99th percentile range for controls.

Profiles of neuromuscular diseases. Duchenne muscular dystrophy.

One hundred and sixty-two patients with Duchenne muscular dystrophy (DMD) were followed over a 10-yr period to provide a profile of impairment and disability. The median height and weight of DMD boys were normally distributed before ages 9-10, but during the second decade height was markedly reduced, and weight was no longer normally distributed. Younger boys gained more weight than normals, whereas older individuals actually showed weight loss. Manual muscle test (MMT) measurements showed loss of strength in a fairly linear fashion from ages 5-13 yr, -0.25 MMT units per year. Upper extremity muscles were stronger than lower extremity muscles, proximal muscle groups were weaker than distal muscle groups, and extensor muscles were weaker than flexor muscles. There was no side dominance. There was a change in the rate of strength loss at 14-15 yr, and the decline slowed to only -0.06 MMT units per year. Although MMT and quantitative strength measurement profiles were similar, the latter were far more sensitive. In general, by the time strength declined to MMT grade 4, isometrically measured strength was 40-50% of normal control values. Joint contractures were rare before age 9, increased in frequency and severity with age, and were present in most individuals older than 13. Lower extremity contractures were strongly related to onset of wheelchair reliance, but there was no association between muscle imbalance around a joint. The prevalence of scoliosis increased between ages 11 and 16, with about 50% of the boys acquiring scoliosis between ages 12 and 15, corresponding to the onset of the adolescent growth spurt. Wheelchair reliance and scoliosis were both age-related. Percent predicted forced vital capacity declined at different yearly rates: ages 7-10, -0.3%; ages 10-20, -8.5%; after age 20, -6.2%. There was a direct relationship between percent predicted FVC and MMT scores. Decreased airway pressures, especially maximal expiratory pressure, appeared earlier than reductions in FVC but followed the same pattern. Thirty percent of the DMD boys had a history of respiratory complications, and the frequency increased with age. Spine deformity did not have a significant additive effect on the age-related decrement in pulmonary function. There was a high occurrence (79%) of abnormal electrocardiograms with age-related progression of some abnormalities, but only 30% of the patients had a history of cardiovascular complications. Functional level grades and timed motor performance measurements had a nonlinear relationship with strength and age.(ABSTRACT TRUNCATED AT 400 WORDS)

Research on Cements for Geothermal and Deep Oil Wells

Abstract This paper describes research relating some of the indicated low strengths of hot-well cements to the CaO/SiO ratio and the amount of A120. An optimum composition was 5 CaO: 6 Si02 plus 7-percent A1203. The A1203 stabilized tobermorite to about 250 deg. C (482 deg. F), without which serious strength loss occurred. Another favorable composition was 2 CaO:3 (SiO2+ A1203), provided at least 5-percent Al O was available in the cement. Six hydrated calcium silicates were found as potential binders in the study. The effect of A1203, ranging from beneficial to deleterious, was determined. Introduction Problems in cementing hot wells increase with increasing well temperature, approximately over the range of 125 to 400 deg. C (257 to 752 deg. F), and increasing bottom-hole pressure. Cement placed at about 125 deg. C may undergo several transformations as the temperature rises to the operating level, including reactions with the additions to cement such as fly ash, residual drilling mud, and the wallrock. This research on calcium silicate cements at temperatures of 150 to 345 deg. C (302 to 653 deg. F) followed two independent but related approaches:measurement of strength as a criterion of quality anddevelopment of the chemistry of the binders and how these related to strength. The results of the chemical studies will be treated in another paper. The time of autoclaving of the strength cubes was necessarily limited to 7 days because of the large number of tests in the program. It was recognized that the equilibrium binders, the ultimate end products in contact with the wallrock for long periods of time at high temperatures, are not always periods of time at high temperatures, are not always attained in 7 days. The slowness of approach to equilibrium of some cements was recently reported by Eilers and Root. As the chemical studies progressed, it became evident that at least six different binders and their Al O-containing counterparts would have to be evaluated for strength. If strength was to be the principal criterion of quality, a massive empirical principal criterion of quality, a massive empirical program of tests would be required. This was program of tests would be required. This was beyond the resources of the project. The most promising approach, particularly in screening out promising approach, particularly in screening out undersirable cements, appeared to be the determination of the potential equilibrium binders in the chemical studies. The starting materials were highly reactive reagent quality CaO, microcrystalline quartz (Tripoli of 8,000-sq cm/gm Blaine fineness), or silicic acid. The water-to-solids ratio was 5.0, and the autoclaving was conducted up to a temperature of 345 deg. (653 deg. F) and for periods up to 35 days. These combinations of materials and conditions generally permitted attainment of equilibrium products in 7 to 10 days. The chemical tests were made on 5-gm samples in small autoclaves. Obviously, such specimens were inadequate for quantitative strength measurements. However, the accumulated actual strengths and relative hardness of the small samples showed a definite correlation. Without exception, pastes that were hard and free from drying shrinkage showed high strengths in the counterpart cubes. It is not intended that such qualitative results serve as a criterion of quality. The relative results are intended as guides for further studies. CEMENTS AND PROCEDURES Portland cement slurries generally lose pumpability rapidly at the higher temperatures of hot pumpability rapidly at the higher temperatures of hot wells. The dicalcium silicates react more slowly than portland cement and were selected in combination with ground quartz for this study. A proprietary cement made from beta 2 CaO SiO and quartz in a CaO/SiO2 ratio (C/S) of 0.85 was used in many tests. The 0.85 C/S composition was modified by adding Ca(OH) for the higher C/S mixes and adding quarts for lower C/S compositions. Gibbsite, A1203 3 H2O, served as the source of A1203. SPEJ P. 307